kunama_wolf

87639 Web Media 2 - Flash course goodness

2009-11-30T02:00:42Z

http://www.shiftperception.com/uts/webmedia2/course-files/

Probably should wget that entire site in case the owner takes it offline or something.

Principles of Forensic Science - 20081023 lecture 20

2008-11-17T04:03:05Z

Principles of Forensic Science - 20081020 lecture 19

2008-11-15T12:30:59Z

Definitions
Evidence: something that has the purpose of persuading the (non)existence of some other fact.
Admissibility of evidence: Evidence needs to be relevant; irrelevant evidence will never have problems of admissibility because they're not admissible. The judge decides the admissibility of evidence, and has the right to dismiss evidence during a hearing, for example, if both defence and prosecution teams object to some item of evidence. The court may not admit evidence if the evidence might be unfairly prejudicial to a party, be misleading/confusing, or be a waste of time.
Weight of evidence: For the jury to decide.
Proceeding: any action taken to bring a matter into dispute before a court. Also known as a matter, hearing or case.
Compellability: a person is a compellable witness if they can legally be forced to testify in court, despite being reluctant to do so.
Subpoena: an official notice requiring someone's appearance in court. According to the Uniform Civil Procedure Act 33.12, failure to comply without lawful excuse is contempt of court, and is punishable by prison sentence. They can show up later to give a reason. To prevent, obstruct or dissuade someone from appearing as a witness or juror without lawful excuse is a crime, punishable by 5 years in jail.
Advocacy: the supporting of a cause. In the context of court, refers to the people involved, particularly the lawyers/barristers of either side.

Legislative provisions
Evidence Act 1995 (NSW)
Evidence Amendment Act 2007 (NSW)
Evidence Act 1995 (Cth)
Uniform Procedure Act 2005 (NSW)

Types of evidence
Testimony
Testimony does not need to be oral; can be evidence written in the first person - an affidavit; I <name> of <address> did see <person> do <action>. These need to be sworn and signed.
Testimonial evidence is adduced and tested via examinations (see below).
Those giving evidence can use charts and other explanatory material if it would help comprehend other evidence going to be/already given.
However, a witness must not use a document to try and revive their memory about a fact or opinion unless given leave by the court. (section 32, Evidence Act 1995)

Admissible Hearsay
Hearsay that is firsthand, eg. I overheard the accused say blah. This is because the truth of evidence must be tested in court; the overhearer will be giving the testimony under oath.
"I overheard person A say that they saw the accused do X" is not 1st hand and would not be admissible; there is no guarantee that person A was telling the truth at the time.

Documents
These are provided before the case hearing starts, at the same time as evidence.

Things
Each one is marked as an exhibit, and is submitted at the beginning of the trial.

Relevant facts
Such as background.

Witnesses
According to section 12 of the Evidence Act 1995:
- every person is competent to give evidence
- anyone who is competent to give evidence, is compellable to give that evidence
The exceptions are (listed in section 13):
- children (who give evidence in another room)
- persons of defective intellect
- those under sentence of death
- the accused
- spouse of the accused - this does not apply in child abuse or domestic violence cases.
- if a person is incapable of understanding that they are under obligation to tell the truth while under oath
- above person may still be capable of giving unsworn evidence if it can be proved that they know the difference between truth and lie, are told they are to tell the truth, and has said that they will not tell a lie
- someone who cannot give a rational reply to a question about a fact, is not competent to give evidence about a fact. They may still be competent to give evidence about other facts. (eg. red-green colourblind person is not competent give evidence as to whether a car is red or green; they are still competent of giving questions as to what model the car was.)
Credibility: refers to a witness's evidence. Includes the ability of the witness to observe or remember facts and events.
Trustworthiness: obviously jurors prefer witnesses who have no apparent bias, interest in the outcome of the case, motive to tailor testimony to support one side, as there is less deception involved.
Expertise: how knowledgeable a witness is about the facts and issues of the case. How well they saw, heard, or knew about relevant events and transactions, how well they remember and recount the details. Impacts upon how knowledgeable the jury perceives a witness to be.

The jury inevitably makes assumptions about a witness as soon as they are seen; this is human nature, and psychologically, it can be important to a case.
They will further judge a witness on their communication skills and attractiveness (both physically and personally); jury members are influenced by people who appear to be much like themselves (in terms of energy, enthusiasm and confidence). Be aware of body language.
A witness with bad character, for example, swears a lot when giving evidence, may be viewed unfavourably.

Oaths and affirmations
Defined in section 1 of Evidence Act 1995
Oath by witness:
"I swear/promise by Almighty God/<some other god recognised by religion> that the evidence I shall give will be the truth, the whole truth and nothing but the truth."
Affirmation by witness:
"I solemnly and sincerely declare and affirm that the evidence I shall give will be the truth, the whole truth and nothing but the truth."

Evidentiary hearings
Hearings that involve, or are based upon evidence.
- Bail application
- Interlocutary proceedings: the in between hearings, between being arrested and when the main case is heard; when the legal representatives come before the judge for administration purposes, eg. when people are ready, is there a set date, etc.
- Chamber hearings
- Court hearings
- Sentencing

Adducing and testing testimonial evidence

Examination in chief

Cross-examination

Re-examination

Leading question: a question that directly or indirectly suggests a particular answer to the question, or makes an assumption to begin with; usually the assumption is in dispute, or the witness has not given evidence to assert it as true. For example, "What was the colour of the car?" is not a leading question; "Was the car blue?" is.
Improper questions can be disallowed by the court, or the court may inform the witness that a question does not need to be answered if it is:
- misleading
- unduly annoying, harassing, intimidating, offensive, oppressive or repetitive.

Miscellaneous information pertaining to evidence/advocacy
- Court attendants are responsible for passing things to the judge/jury/witness.
- Barristers in Australia are required to stay behind the bar. They also wear wigs.
- Judges also wear wigs.
- Wigs are worn for the protection of identity, while also identifying a barrister as a barrister. A wig is considered a 'tool of the trade'.
- Solicitors do not wear a wig.

Principles of Forensic Science - 200810116 lecture 18

2008-11-15T07:07:03Z

Definitions
Tort: a wrong committed by a legal person to another legal person. A civil offence that can result in a civil lawsuit.
Legal person: probably better named 'legal entity'. An individual, a business, an organisation. One has no legal rights until one has actually been born and taken their first breath.
Reasonable person: the average person, except in professional cases, where the reasonable person would be one's professional peers. (Same as criminal.)
Plaintiff: the one suing. Usually the victim.
Defendant/respondant: the one being sued.
Privacy: how information is managed, collected, stored and used.
Confidentiality: Trust and respect; ensures patients are protected from harm from disclosure.
Privacy and Confidentiality are NOT the same things.

Legislative provisions
Civil Procedure Act 2005 (NSW) - Civil proceedings in general
Civil Liability Act 2002 (NSW) - particular to Negligence

Civil process
1. Statement of claim (not an arrest). This needs to be physically presented to someone, it cannot be done by mail. Some people try to avoid this by running away overseas so that proceedings cannot begin.
2. The parties go to court. There is NO JURY; jury is only for criminal proceedings.
3. The court may recommend mediation sessions.

Miscellaneous information
- Assault and battery is a civil and criminal offence. For example, it may be more effective to get money from the accused rather than sending them to jail.
- Civil proceedings are usually seeking financial compensation for economic and non-economic losses.
- Aim is to restore the injured party to the position they would have been in, but for the wrong (the position the injured party would be in if the wrong had not occurred).
- Intention is irrelevant.

Burden of proof
A balance of probabilities; the likelihood that something happened, vs the likelihood that it did not happen.
There is no need to prove it beyond reasonable doubt.

Some types of tort
Trespass
Can be against
- person
- land
- goods

Assault
Does not actually require physical contact.
Victim is in a psychological state of apprehension (not fear) - aware of the imminence of a harmful or offensive act.
Perhaps applicable in the cases of sport, where consent is implied?

Battery
Proof of contact is required, along with the intent; the victim does not actually need to prove injury. Because this is tort, negligence is good enough for the intent in Australia.

Defamation
May be tied in with issues around confidentiality and the breaching of confidentiality.

False imprisonment
Where a person is intentionally confined without legal authority.

Nuisance
For example, loud raucous parties, poisonous industrial waste that flows past one's property.

Conversion

Detinue

Negligence - aka carelessness
The omission to do something which a reasonable person would do, or a reasonable person would not do.
Simpler: Conduct falling below a standard regarded as reasonable.
First encountered in the 'snail in the bottle' case - Donoghue v Stevenson [1932] AC 562 ; basically, ginger beer was purchased, drunk, and a decomposing snail was found in the bottom of the bottle, the result was gastroenteritis and shock.

Time limits: 6 years avg, but ranges from 3-12 years; each case is decided by the court depending on the circumstances. The exception is dust diseases, on which there is no cap on time or damages able to be awarded.
Reasonable person test: a reasonable person takes reasonable precautions against reasonably foreseeable risks.
Neighbour principle, simplified: do no harm to those that one comes into contact with.

Elements of negligence, aka Things that need to be proved
- Duty of care. Need to prove that the victim was owed a duty of care.
Reasonable care to be given by a reasonable professional. For example, to exercise the skill that a reasonable forensic scientist professing to have the skills in question would do, if put in a similar situation.
The standard is obtained from professional peers deemed to be experts in the field.

- Breach of duty. Plaintiff must prove that the negligence did in fact cause the injuries.
Would the plaintiff's injuries have been suffered but for the defendant's negligence?
If the injuries would have happened regardless of negligence, then negligence is not the cause.

- Damage. Harm suffered must be of a foreseeable nature; needs to have been probably and possible; there must be actual cause and effect. However, the one who has breached duty of care does not have to have foreseen the exact nature of the damage.
Test of foreseeability: would the reasonable person in the position of the defendant, have appreciated that her/his actions might cause injury to the plaintiff?

Defences for Negligence

Voluntary assumption of risk

Contributory negligence

Statute of limitations

Illegal activity

Types of negligence

Negligent misstatement

Vicarious liability

Other key points from the Civil Liability Act 2002 (NSW)
- 18 June 2002
- Max damages for non-economic loss is fixed (currently, $450,000); 15% threshhold
- Max damages for economic loss due to loss of earnings, in NSW is 3* average weekly earnings
- There are limits on the rights of intoxicated persons, criminals and nervous shock claimants.
- witnesses, both expert and lay, are protected from civil action while giving evidence during court proceedings; this is so witnesses are able to give evidence fearlessly; cross examination and confrontation aspects of trial are meant to safeguard against careless, malicious and untruthful evidence.
- One can try to sue for perjury, but it's very difficult to prove; criminal liability, requires proof of conflict of interests/documents showing it.

Points specific to professionals
See: The Australian and New Zealand Forensic Science Society Code of Ethics
- A professional does not incur a liability on negligence if it is established that the professional acted in a manner that is considered competent professional practice when providing the service.
- Forensic experts performing work not intimately connected with litigation may be the subject of negligence actions. Similar to how barristers and solicitors are liable for giving out of court legal advice.
- Expert evidence presented to the court should be, and should be seen to be, the independent product of the expert uninfluenced as to form or content (ie. not affected by how much they're being paid)
- An expert witness should only provide evidence within their area of expertise. They should make it clear when questions fall outside their expertise. (None of this calling up of physicists to say HIV is not transmitted by sexual contact!)

Principles of Forensic Science - 20081013 lecture 17

2008-11-14T20:41:04Z

Definitions
Crime, aka offence: a legal wrong that may be followed by criminal proceedings, possibly resulting in punishment. An act condemned sufficiently strongly to have induced legislature or judges to declare it punishable before the courts. A wrong committed against The People (hence their citations are <accused> vs Rex/Regina). Often comes with an act and a mental state.
Summary offence: lesser charges, eg. speeding
Indictable offence: sentence is 2 or more years in jail
Actus Reus: guilty act. Physical element. The committing act. eg. I robbed.
Mens Reus: guilty mind. Fault element. The state of mind, which may determine the culpability (how much the person is at fault), eg. intent vs recklessness (chose to risk committing the act). For example, an awareness of the likelihood of causing death is sufficient for the crime of murder; even if the accused had no wish to kill, this has no bearing on the fact that the accused actually ended someone's life (manslaughter).
Reasonable person: usually the 'average joe', not an ex-prisoner. In cases involving professionals, another of similar expertise.
Recklessness: the unreasonable or unjustifiable taking of a risk known by the accused. The recognition of a risk but the decision to continue regardless. Differs from intention in that intention only occurs when it is known or virtually certain that a specific consequence will follow.
Penalty unit: $110

Arms of government
Legislative - law making. Parliament; Senate and House of Representatives.
Executive - formation of policy and administration of laws. The police.
Judicial - interpretation and application of law. The courts.

Judicial arm cannot create new categories of offence.
Legislature creates new offences.

Standard of Proof
Criminals are innocent until proven guilty.
Prosecution must prove the guilt of the accused "beyond a reasonable doubt"
Thus, the prosecution runs the case.
There must be sufficient foundation of evidence for every issue alleged. If judge considers that there has been insufficient evidence presented, the jury will not be allowed to consider the issue.
Burden: to convict someone of a crime, the facts must be established and then applied to the appropriate rule of law, ie. The accused broke law X.
Legal burden of proof: The prosecution must prove that a law has been broken by the accused, and persuade the jury that the accused is guilty.

Criminal liability
- A person must have the legal capacity to commit a criminal offence.
- Actus Reus; the person must have actually committed the offence. Conduct/Physical elements.
- Mens Rea; the person must have intended to commit the offence. Fault elements.
- The absence of any defences of excuse or justification
Both conduct and fault elements need to be present, and need to be present at the same time.
For example, person A formed an intention to kill person B, and then later kills person B accidentally, does not commit murder.

Legislative provisions
What a crime is has been defined in:
- Crimes Act 1900 (NSW)
- Crims Act 1914 (Cth)
- Case Law

Criminal process
1. Arrest and escorted to the police station
2. Bail may be granted by the senior constable or a magistrate; generally dependant upon how dangerous the accused is considered to society
3. Date is set for a court hearing.

Defences - see Part 11 of Crimes Act 1900 (Cth)
Duress
The committing of a crime under threat of injury to the accused or some other person should the accused refuse to obey the threatener.
Dominant psychological state: fear.
A choice between two evils - commit a crime, or have what is being threatened occur.

Necessity
The committing of a crime under sudden or extraordinary emergency circumstances.
For example, the separation of siamese twins, in which both will die if they remain conjoined, or one will die if separated.

Provocation
A way to reduce a sentence from murder to manslaughter.
Any conduct that deprives an ordinary person of self control. Commonly, assault, sexual infidelity, verbal abuse.

Intoxication
Not a defence in itself.
Can negate the mental element, or other essential requirements for criminal responsibility.

Unintentional intoxication
For example, accused was drugged.
Can negate criminal responsibility for Commonwealth offences in NSW, or reduce one's sentence.

Insanity
The term is no longer used, having been replaced by phrases such as "mental impairment", "mental illness", "mental incompetence" or "unsoundness of mind".
Refers to a degree of incapacitation caused by mental illness in such a way as to prevent criminal responsibility.
Being mentally ill is not in itself an excuse for committing a crime.

Automatism
The unwilled performance of simple or complex movements of the body in a state of defective consciousness.
Implies complete, not partial, loss of self-control.
Accused may be aware of the nature and wrongfulness of their conduct, but cannot control themselves.
For example, involuntary reflex; tourette's syndrome; sleepwalking.
Legally significant: a person is not responsible for an involuntary act.

Diminished responsibility
A partial defence to murder; reduces the accusation to voluntary manslaughter.
A defence to all species of murder, including felony murder, but cannot be used as a defence for crimes not classified as murder.
For example, brain damage; epilepsy; emotional instability; battered women's syndrome

Self defence - see part 11 division 3 of Crimes Act 1900 (NSW)
Valid when equal and reasonable force is used.
For example, self defence would not work very well if the accused had a shotgun against a person armed only with their fists.

Offences against the person
There are two broad categories: incipient (not actualised) violence, and actual violence.
Thus, threats by words or conduct may constitute a criminal offence, independent of assault.

Assault
An act by which a person intentionally or recklessly causes another to become aware of immediate and unlawful violence.
Physical contact or application of force is not required; mental assault is possible, such as harassment, stalking, the causing of psychological fear.
Physical assault is also called battery.

Two broad categories: common assault; aggravated assault.
Fault element of an assault (mens reas): the intention to commit an assault, or by reckless indifference as to whether or not assault occurs.

In cases of psychological assault, there needs to be proof that the victim was aware that they were the object of the defendant's offensive conduct.

Stalking is the intent to cause the victim to fear personal injury; the activities that come with the offence include following a person, watching/frequenting the vicinity of a person's residence, ... or any place that a person frequents for the purposes of any social or leisure activity.

Grievous bodily harm is physical injury of a really serious nature (well duh).
Consent is not a defence to this charge.
It must cause the skin to break; there must be intention.
Includes the loss of a foetus, or causing someone to contract a grievous bodily disease.

Robbery
A felonious and violent taking of any money or goods from the person of another, putting him in fear.
1. Felonious intent, aka. animus furandi.
2. Violence, or causing of fear
3. Taking of stuff

Forgery/counterfeiting
The alteration must have, or be intended to have, some material effect on a person who might rely upon it.
For example, signing a document with a fictitious but material name constitutes a forgery.

Other miscellaneous things that have a part in criminal law
A motive for murder is not required. The intent to kill is.
Involuntary manslaughter is not as serious as manslaughter.
Involuntary manslaughter would be something like accidentally running someone over in a car.

Principles of Forensic Science - 20081011 lecture 16

2008-11-14T09:15:06Z

Act: legislation, passed through politics.
Judges: responsible for the interpretation of law
Jurisprudence: philosophy of what law is or should be
Law: rules enforceable in a court of law. NOT the same thing as justice.
Morals: principles of right and wrong conduct that contribute to one's character
Ethics: a system built on moral principles, upon which human actions and proposals may be judged good/bad, right/wrong, and moral duties and obligations are established. Acting ethically is to act in accordance with the rules/standards for right conduct/practice, especially in regards to a profession; a Code of Ethics is enforceable in most professions, but unlike Accounts, Lawyers or Doctors, there is no governing body for cases of professional misconduct in Science. (That's not to say that a Scientist cannot be publically shamed by the media; it just means that they can continue as a Scientist regardless.)
Privileged information: like confession; does not need to be reported. Is the case between lawyer and client. Is not the case between patient and doctor.
Statute law: legislation, acts of parliament
Case law: law made by judges
Jurisdiction: area of law. "NSW does not have jurisdiction over QLD" is geographical; "Local court has no jurisdiction over the High Court" is allocative, in regards to court hierarchy.
Judicial precedent: Lower courts must follow the decisions made by a higher court.

Purpose of law
- To control society
- Regulate conduct
- Protect citizens and property
- Provide a set of rules governing relationships between government and citizens, citizens and other citizens, treaties ratified by Australia
- Provides a means to resolve disputes, punish offenders, adjudication and settlement through the courts

Influences on law
- religion
- history
- politics
- economy
- British law system (historically Australia's law is based off theirs)
- Developments in Australia and internationally

Hierarchy of Federal and State courts

Image belongs to Werdna
The High Court is the guardian of the constitution; the Commonwealth parliament cannot abolish the High Court.
Their powers are listed in section 51 of the Constitution.
The High Court has 7 judges, but not all sit at once; that tends only to happen when test cases are being heard.

Arms of government
Legislative - law making. Parliament; Senate and House of Representatives.
Executive - formation of policy and administration of laws. The police.
Judicial - interpretation and application of law. The courts.

Citations

Burrell v The Queen [2008] HCA 34 (31 July 2008)
Accused: Burrell
Respondent: The Queen; represents the people; this is a criminal case.
Case decided in 1973 in the High Court of Australia, 34th case to be decided (not heard!), sentence released to the public on 31 July 2008

Waltons v Maher (1988) 164 CLR 387
Applicant/Plaintiff: Waltons. The one who took action.
Defendant/Respondant: Maher. The accused.
Decided in: 1988
Volume 164 of the Commonwealth Law Reports starting on page 387. (The year will be on the spine of the book)

Common abbreviations
v: Versus, but referred to as "and" in law
R: The Queen/Rex/Regina/The Crown; represents the people, and denotes a criminal case
JJ: judges
QC: Queen's Counsel; also called Senior Council. Highly paid; the position was overturned by Keating.
Catchwords: summary of the decision.

Citations refer to decisions made; these are public, and published. There is extensive work that goes into them, and judges who sat to hear the case can all have a say when it is published; alternately, they may all join together to make a statement.
A decision is usually backed up by references to other court decisions.

Miscellaneous
Judges retire when 70 years old.
An appeal needs to be made within 28 days.
There needs to be a point in an error of law if one wants to appeal. One cannot just appeal because they didn't like the decision, they need to be able to say that something was done wrongly in the decision made according to the law.
Forensic scientists are not adversaries; that is the job of the lawyers.

Principles of Forensic Science - 20080908 lecture 15

2008-11-14T05:46:15Z

Principles of Forensic Science - 20080911 lecture 14

2008-11-14T05:45:17Z

Definitions
Toxicology: the study of poisons and their effects upon the processes of the body.
Forensic toxicology: the study and practice of the application of toxicology to the purposes of law. (American Board of Forensic Toxicology)
Poison: "All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy." (Peracelsus, 1493-1541)
Xenobiotics: things foreign to the body. A class of poison.
Pharmokinetics: what the body does to the poison. Generally, absorption, distribution, metabolism and excretion.
- Absorption: how stuff gets into the body; unless IV injection, things must pass through a cell membrane, and therefore its chemical structure determines how easily a drug gets though.
- Distribution: how a drug travels through (or remains) the body, eg. through blood, stays in fat, etc.
- Metabolism: chemical or physical changes that the body makes upon the drug.
- Excretion: the expelling of the drug (or what it's become) from the body
Pharmodynamics: what the poison does to the body. Mode of action (usually by binding themselves to the body's receptors so that there is some effect); toxicity.

Miscellaneous information related to toxicology
Toxins need to get into the bloodstream to have major effect.
Most drugs used for drug facilitated sexual assault are water soluble.

Analysis
Involves sampling and sample preparation
Identification, quantification, quality assurance and measurement methods
Interpretation of results

Legal system
???

Poisons
Therapeutic drugs
Industrial chemicals
Environmental pollutants
Household poisons
Natural toxins

Principles of Forensic Science - 20080915 lecture 13

2008-11-14T05:41:29Z

I'm still really irritated by the lack of objectivity during this lecture.

Principles of Forensic Science - 20080825 lecture 12

2008-11-11T12:48:55Z

Definitions

Combustion: the exothermic reaction between a fuel and an external oxidising agent (usually atmospheric oxygen).

Explosion: rapid combustion.

Fuels:
- Cellulosic polymers (wood, paper, cotton, rayon); cellulose is the largest % of stuff on the planet
- Artificial polymers (polyester, nylon, PVC)
- Flammable liquids (hydrocarbons, alcohols, esters, ketones)
- Flammable gases (methane, acetylene, hydrogen)

Fire seat: The point from which the fire has spread. Point of origin, or a spot fire started from debris. Identify it via:
- points of low burning. First, most obvious, most important sign of a fire seat. Fire always burns faster upwards than it does sideways or down; low burning patterns point to origins. Unfortunately these also tend to be located under debris.
- patterns of high burning. Highest temperatures in a fire plume are located above the fire. However, temperatures are also higher at escape/ventilation points.
- smoke and soot patterns. The result of poorly ventilated fires. Patterns point back to the direction where the smoke and flame originally came from. However, soot may burn off when the fire temperature rises; a ventilated fire results in little or no soot.
- burn patterns on walls, floors and in wood. Localised failure; V shaped burn patterns
- heat effects on glass, structural metals, metal fittings and plastics
A fire can have multiple fire seats.

The law side
Orgs involved: police, insurance companies, fire brigades
Fire investigation tends to have much to do with civil litigation. (See lectures on law)
An investigator may work for either side; police or insurance companies.
Important things to note are that in court, key points are the facts and the likely cause; it does not need to be proved beyond all doubt.
Negligence is something not performed.
Recklessness is something not performed, that affected more than was necessary.
Ultimate issue: do not say that X is guilty or innocent; "The evidence strongly suggests that X was at the scene and did action Y."
Coronial inquest: where the coroner can ask any questions necessary to find out why the victim died. All those involved may send a representative in to question the witness; the idea is to keep asking questions until all the facts are found.
Fire investigator determines how a fire has spread, to work back to the source of the fire and determine its most likely cause. This is done by collecting evidence, drawing conclusions from the facts and providing written statements about the conclusions.
Coroner inquires into the circumstances surrounding deaths reported to them. Determines the identity of the deceased, inquires into the time, place, cause and manner of death, and refers the matter to Director of Public Prosecution if the death is connected to a crime. In a coronial inquest, the coroner decides if something is beyond all doubt; probabilities are of importance.
Fire investigators have a lot of contact with the coroner.

Intent
Least severe to most severe:
Intent to destroy property
Intent to destroy property for personal gain (eg. insurance fraud, which is both a criminal offence and a civil matter between defendant and insurance company
Intent to harm a person

Costs of a fire
Direct cost: eg. building is gone, several million dollars worth of infrastructure.
Indirect cost: eg. no business for 12 months while relocation to a new building occurs.
Suppression cost: the cost of suppressing the fire, eg. fire brigade maintenance.
Prevention cost: the cost of preventing fires, eg. every level of a building is built specifically to be fire retardant.

Types of fire

Fire type	Amount of danger	Common ignition sources	Remarks
Structure fires: buildings.	The most dangerous to people. Minority fires kill the most people.	Dropped cigarettes, followed by incendiary/suspicious.	Most structure happen in domestic dwellings, in the kitchen; however, the kitchen fires are not the lethal ones. Upholstered furniture and bedding burns well. Minority fires, such as massive buildings going up in flames, are the lethal ones.
Non-residential: eg. factories.	Not often fatal; none in buildings fitted with sprinkler systems that worked during a fire.	Incendiary/suspicious, then electrical.	Often high costs are involved; arson is a major cause.
Lightning strike fires	Depends on area and level of preparation	Lightning strikes, duh	Unique to Australia

Living requirements for a fire

Ignition

autoignition

shock

Propagation

Energy

Oxygen

Fuel

Convection

Density gradient

Radiation

Other fire effects

Pyrolysis gases
Pyrolysis is the decomposition of a chemical by extreme heat. When an organic solid undergoes pyrolysis, it becomes more like carbon. Some of the other stuff that is not carbon turns into pyrolysis gases.
Heat + organic solid -> solid + other stuff (which may contain pyrolysis gases)
Note lack of oxygen required for the process.
Gaseous products of pyrolysis vary according to the solid.
- Can spread a fire (they're hot)
- Generally toxic (people need treatment for "smoke inhalation", because they've been inhaling toxic gases)
- Can cause fatalities (CO and cyanide are both possible pyrolysis gases; being hot, gases can also burn the lungs.)
- Can be combustible (but they don't have to ignite immediately after formation)

Radiation flux
The measure of the flow of radiation from a given radioactive source; in this context, the source is the fire, radiating heat energy. Its units are kilowatts per metre square.
Radiation flux is proportional to fire size; as fire gets bigger, radiation flux increases.
Bushfires have no limit on the fire size; similarly, radiation flux; objects 100m ahead of the flame front can be ignited by radiation.

5 kW/m^2: limit of safe exposure for skin. Corresponds to low fire temperatures, meaning people are at risk from any flame closeby.
12.5 kW/m^2: charring of timber surfaces.
25-30 kW/m^2: in a compartment fire, all flammable vapours, surfaces and pyrolysis gases will reach autoignition temperature; everything in the compartment catches fire.

Stages of a fire

Ignition
* Fire easily prevented if noticed, but often goes unnoticed.
* Easily extinguishable with portable firefighting equipment.
* Seat of the fire is readily apparent; ignition source still intact.
Ignition source/point is usually the smallest event.

Small fire stage

Smouldering fire
- Solid fuel, heat limited.
- Energy limited fire is more likely an accidental one.
- Slow burn can continue for hours.
- Pyrolysis occurs.
- No radiation effects.
- Fire seat is most intensely damaged point
- Only one part of compartment showing damage
- May just die out due to heat loss or lack of fuel.
- May gain enough heat to become a flaming fire.
* Fire may go unnoticed; easily extinguishable, but toxic hazards due to pyrolysis
* Extinguishable with portable firefighting equipment; low visibility; uncertainty as to whether the fire is completely out
* Intense, local damage which may destroy the ignition point; easy to locate fire seat; obvious ignition source.

Flaming fire
- Not necessary intentional; just needs to be unconstrained.
* Easily noticed; not so easily extinguished; can grow exponentially; can kill via radiant heat, pyrolysis gases, or inhaling hot gases.
* Extinguishable with an attack hose line, or concentrating water spray on flames when properly equipped.
* Travels quickly, producing burn and smoke patterns that point to the fire seat; fire seat covered in debris, ignition source destroyed.

Flashover
- Flaming fire reaches compartment ceiling and spreads across it, following convection flow paths.
- Pyrolysis gases at the ceiling ignite if there is sufficient oxygen
- Radiation flux increases rapidly until 25-30 kW/m^2.
- All flammable solids and gases ignite.
- Windows, doors, ceilings fail; fire passes ventilation-limited state.
- Fire is not constrained to 'contents of the compartment', but becomes a 'compartments in the structure' fire.
- Structural failure starts here.
* No survival in a compartment that has reached flashover.
* External, defensive firefighting with hose lines required; firefighters have seconds to evacuate if they are in the compartment and have full protective gear; the building can collapse at any point after a compartment reaches flashover
* Evidence is progressively destroyed, everything merges into radiation patterns; liquid accelerant will probably not survive for collection and analysis.

Structural damage and failure
Spall: heating of stuff that isn't flexible to expanding; progressive cracking off due to a bit heating and expanding when nothing else can. Happens to cement, concrete, masonry.
- Steel expands, damages surrounding structural components; permanently weakened when exposed to >500 °C
- Wooden beams char
- Non-structural ventilation points fail
- Ceiling or roof fails
- Walls may fall as the roof falls
- Fire starts to die due to lack of fuel, but can continue for quite a while; burning through entire buildings is possible
* Access impossible for firefighters; fire will die due to lack of fuel once collapse happens; external firefighting
* Fire and water damage destroys evidence; fire seat impossible to locate; picking through the structure's remains is painstaking; ignition source will probably never be confirmed

Investigation
Treat the fire scene as if it were the crime scene; it may turn out to be.
Be aware of safety
Photography is difficult; black on black on black.
Do not use flash unless declared safe by firefighters; flammable vapours may be present. Video is better anyway, as it can record in infrared.

Evidence
- Ignition source identified at the fire seat
- Suspicious powders at the source
- If liquid accelerant is suspected, collect material (absorbant is good) from the edge of the fire seat (carpet, upholstery) or protected areas (under furniture, bodies)
- Control samples of any material from places definitely not the fire seat; remember to package separately
- Suspects' clothing, particularly rubber-soled shoes, which retain flammable liquids well

Causes of fire
Accidental: when fuel loads are high, whether domestic, industrial or commercial, one cannot assume arson solely based on fire spread or intensity.
In domestic cases, if a stove, bed or couch is the fire seat, then accidental is the first suspect unless definite signs of arson are present.
In industrial cases, if there is an excess of fuel available (tyre dumps, hydrocarbon processing plants), then building design or sprinkler systems are not likely to prevent fires from spreading once ignition has happened.

Electrical
The hardest to prove. Fundamental problem: did the wire short out and ignite the fire, or did the fire cause the wires to short out?

Arson
Circumstantial evidence:
- Repeated fires, on the same target; a pattern of similar fires in the area. Ask the firefighters.
- Inappropriate preparation, eg. being fully dressed at night; valuables, sentimentals and pets removed from the house; stereos and tires removed before setting a vehicle on fire
- Specifically targeted fire, eg. Financial sections prior to an audit
Physical evidence:
- Multiple, independent fire seats. The most compelling evidence for arson.
- Evidence of trailers. A trail of flammable stuff, used to link multiple fire seats or act like a fuse. They leave distinctive burn patterns on the floor or ground.
- Extraneous material at the fire seat. Piling up of fuel by arsonists. In a targeted fire, the target item/material may be piled at the fire seat.
- Evidence of material missing from the scene. Fraudulent removal of items by the 'victim', or 'stolen' by an 'external arsonist'.
- Evidence of sabotage. Forced entry (ask the firefighters), sprinklers not working.
- Ignition source. If identified, can be clear evidence of arson. eg. Time delay devices, flammable liquids in an inappropriate location (petrol in the garage, normal; in the lounge room, wtf?), flammable liquids stored inappropriately (no one stores open jerrycans of fuel, even in the garage)

Principles of Forensic Science - 20080904 lecture 11

2008-11-11T12:19:51Z

Principles of Forensic Science - 20080828 lecture 10

2008-11-11T12:18:23Z

Guest lecture by Peter Gunn, Senior operations officer, Forensic biology unit, NSW Police Force

Not examinable in final exam

Principles of Forensic Science - 20080901 lecture 9

2008-11-11T12:16:29Z

Principles of Forensic Science - 20080821 lecture 8

2008-11-09T14:04:30Z

Images from Xanthe Spindler's lecture notes.

Fingerprint: The mark produced by contact between papillary ridges on the finger and a surface (both porous and non-porous surfaces).
Prints do not always have to be from a finger, but the pattern of the papillary ridges on the fingers are the ones used for individualisation.

Latent fingerprint: most common, usually contains secretions of some kind.
Eccrine secretions - salt, water, amino acids, sugars. Almost always present.
Sebaceous secretions - fatty acids, lipids, alcohols
Apocrine secretions - proteins, iron, water, carbohydrates. Linked to puberty, and are therefore not often secreted by prepubescent children.
Plastic fingerprint: prints upon surfaces or material that has retained the print detail. Wax, thick grease, etc.
Visible fingerprint: transfer of a foreign material on the finger to the surface. Generally photograph required only.

Any surface will take a print. Prints just don't last very long on some of them.

Lophoscopy: development, classification and identification of prints left by secretions and contaminations of the papillary ridges of the skin
Dactyloscopy: the study of fingerprints. An area of lophoscopy.

Characteristics of fingerprints
Unique - general pattern is determined by genetics, but the minutiae are caused by random pressures in the womb; twins have unique fingerprints.

Immutable - patterns are formed deep in the dermis, and cannot be altered, other than through accidents or serious skin disease, and accidents; both these cases will also leave unique prints.

Unchanging - because they are located deep in the dermis, once formed, they do not change.

Universal - everyone's got fingers.

Easy to classify - see classification, below.

Classification of fingerprints
A great number used, most of them based on Galton-Henry and Vucetich.

Au uses the Galton-Henry system, which is dependant on the identification of a core, a delta, and then minutiae for individualisation.

Identification of fingerprints
General to particular:
1. first level detail - class characteristics
2. second level detail - minutiae analysed
3. third level detail - pore size and distribution along papillary ridges

Minutiae

Bifurcation

Island

Ridge ending

Enclosure (see above general minutiae image)

Type line: the two innermost ridges that start parallel, diverge and surround the pattern area. A triangular area.

Delta: the point on a ridge that is nearest to, and in front of, the divergence of the type lines. If the delta is on a bifurcation, the bifurcation must open towards the core. The delta is always on the end of a ridge. Bifurcations take precedence over ridges for delta placement.

Core: where the innermost recurve begins turning to go back the way it came in. Place at the innermost point where it begins to turn; alternately, place on the end of a rod/ridge located within the curve. If there are two rods, place it at the top of the rod further away from the delta. If there are multiple rods, place upon the middle one; alternately, if an even number, treat the center ones as though there were 2 rods. The core may only be placed on or within a recurving ridge.

Class characteristics

Arches - no type lines, deltas or cores. 5%.
Subclasses: plain and tented. (see below image)
Tented arch has ridges that meet at an angle <90 degrees.

Loops - type lines, 1 delta, 1 core, ≥1 ridge count, ≥1 ridges entering from one side of print, recurving and exiting from the same side. 60%.
Subclasses: ulnar and radial.
Ulnar loop opens towards the little finger, or ulnar bone.
Radial loop opens towards the thumb, or radial bone.
Therefore the subclass is dependant upon the hand the print was taken from.

Ulnar and radial loops for right handed finger.

Whorls - type lines, ±2 deltas. 35%
Subclasses: plain, central pocket, double loop, accidental loop

Plain whorl - ±1 ridge making a complete circuit. If a line is drawn between the 2 deltas and it touches any of the spiral ridges, then plain whorl.

Central pocket whorl - If a line is drawn between the 2 deltas that does not touch a spiral ridge, then central pocket whorl.

Double loop

Accidentals - two or more patterns; alternately, everything else not classified under the other categories.

eg. loop over tented arch

ACE-V methodology
Analysis - can print be used for identification? (quality)
Comparison - is there a match between reference prints and prints gathered as evidence?
Evaluation - are there enough matches in the minutiae to conclude identification; alternately, are there enough differences to conclude exclusion? More matches/differences is better, but do they meet the minimum number required? (# required in au is different to # required in fr)
Verification - did another analyst come to the same conclusions

Enhancing latent fingerprints
Technique used is dependant on the estimated age of the fingerprint, and the surface it is located on.

Powdering: non porous surfaces
Cyanoacrylate (superglue): non porous surfaces, smaller items, fluorescent dyes
Ninhydrin: porous surfaces, print is purple
DFO: porous surfaces, print is fluorescent faint pink
Indanedione-zinc: for difficult porous surfaces, print is fluorescent bright pink
Amido black: non-porous surfaces, print is dark blue, mostly for blood, and reacts with proteins
Gentian violet: for sticky tape, print is dark purple, reacts with proteins
Physical developer: wet or old documents, print is silver/black

History of dactyloscopy
BC - People were aware of the individuality of fingerprints; see Wikipedia for more detail.

1684 Nehemiah Grew
- study of the anatomy of hands and feet

1823 Johannes Purkinje
- Classified fingerprints into groups (there are less used in Au these days)

1833-1917 Sir William Herschel
- Tried to get fingerprinting used as the method of identification in India; was unsuccessful
- Experiments to establish unchanging nature of papillary ridges

1843-1930 Dr Henry Fauld
- Hypothesised that the offender could be identified by fingerprints on the scene
- Sent letters but got no reply; published his findings from 22 years in Inida; debate ensues between Fauld and Herschel about individuality of fingerprints

1881 Alphonse Bertillon
- Anthropometry: methodical measurement of anatomy to identify repeat offenders. Problem was, people change as they age.
- Portrait Parlé: part of it was a standard language used to describe anatomy, some of which is still used today

1888-1892 Sir Francis Galton
- Evaluated anthropometry and dactyloscopy, at first considering dactyloscopy as a compliment to anthropometry but later being convinced of dactyloscopy's superiority over anthropometry
- Separation of papillary patterns into 41 classes
- Stated that the patterns were immutable, unique, unchanging and that there was potential to classify a large quantity of them

1894-1897 Sir Edward Henry
- Inspector General of police in Bengal, India
- Tested anthropometry techniques and doubted their reproducibility
- Simplification of Galton's classification system, resulting in the development of Henry's classification system
- 1897 India officially discarded anthropometry for fingerprints and Henry's system

1891, 1893, 1896 Juan Vucetich
- Different classification system developed after looking at Galton's notes
- 1893 Rojas murder case solved using fingerprint evidence, subsequently presented at symposia, demonstrating superiority over anthropometry
- 1896 Argentina abandons anthropometry and uses Vucetich system

1901-1924 Adoption of fingerprinting
- 1892 Galton convinces British government to supplement anthropometry with dactyloscopy
- 1901 a comparison of anthropometry and dactyloscopy is conducted, concludes that dactyloscopy should be used
- 1901 Henry-Galton system adopted by Scotland Yard
- 1901 New York City Civil Service Commission adopts fingerprinting
- 1903 A new prisoner identified as the already incarcerated William West by anthropometry measurements; the system is abandoned altogether
- 1904 Yvert, student of Locard, suggests replacement of anthropometry with dactyloscopy, but maintaining portrait parlé; 5 years later, Locard is also convinced
- 1903-1912 Australia state police introduces fingerprinting services
- 1910 US murder trial identifies offender using fingerprints
- 1914 International Police Congress held in Monaco, decides on a standard dactyloscopic identification form, retains certain aspects of portrait parlé
- World War 1 each country decides to develop their own dactyloscopic systems (wtf)
- 1924 FBI database established

Now
- Numerous fingerprint classification systems in use
- Different rates of advance in fingerprint technologies
- (N)AFIS - (National) Automatic Fingerprint Identification Systems available
- Fingerprint research occurs mainly in the following countries:
Switzerland, chemical enhancement and identification systems
Australia, chemical and light enhancement
USA, chemical enhancement and standardisation techniques
England, enhancement and reliability studies and identification systems
Israel, chemical enhancement
(Interestingly, India, while one of the first countries to pick up the technology, seems to have been left behind.)

Principles of Forensic Science - 20080818 lecture 7

2008-11-09T14:03:22Z

2 Guest speakers from the NSW Police Force, Forensic Services Group, Crime Scene Services branch, Forensic Imaging.

Generally done by civilians, not sworn officers.
Specialisation is important; one is less likely to be looked down upon in court for not knowing what one is on about.

Photography
There is a studio for exhibit photography.

Police force uses digital, but the courts still prefer film.
Injury/assault photography requires specialist lighting.

Never edit the original photograph. Always modify a copy.

Photographic evidence to still be valid in the courts even after image rectification, scale prints, and corrections for wide angle distortion.

Rectified photos of, for example, shoe prints, can result in confessions.
Orthophotographs of, for example, The Gap at Watson's Bay can be used to accurately measure the distances, and in the case of people going over the cliff, possibilities of certain scenarios being true.

Image enhancement is another matter; generally only contrast, image quality and the fixing of colours occurs; anything more may be considered questionable in court.

Sometimes images are edited so that the jury is not overly affected by the shock value of, for example, very graphic photos. For example, an image would be edited for the purposes of pointing out the stab wounds on a really bad burn victim, to ensure the jury do not get overly hung up on the fact that the corpse is a charred, blackened mess.

comfit is a program used to build faces. Its main use is for investigation or memory jogging purposes. There are attempts to link it to facial recognition software.

Aging simulations exist, mostly for the purposes of simulating what a missing person might look like several years down the track.

Video
Video services is mostly for live work with people; they may video an interview or visit to the scene with a witness. Video can be used for walkthroughs, and may be used in court; however, because of the impact a video of a victim explaining something that happened can have on the jury, the courts are wary of such.
CCTV is prevalent for video. The video people also do a lot of blurring for identity protection purposes, and dubbing/copying existing video.
There are also attempts to superposition faces from video onto official photos taken of a suspect. So far this is still very angle dependant.

Advantages of video include:
- unbiased
- doesn't stop halfway through
- can refresh memory
- is more realistic
- video re-enactment, for the purposes of assessing speed and confirming given statements

Other teams
- Compositing - multiple sources pulled together into one.
- Survey - prettying up of sketches, reconstruction, CAD, 3D modelling, ortho photos of blood/projectile for trajectory interpretations.

Principles of Forensic Science - 20080811, 20080814 lecture 5 and 6

2008-11-07T06:06:07Z

The goal of crime scene investigation:
- to reconstruct events
- identify identities of those involved
by using the evidence collected at the scene.
Questions:
- Who was involved?
- What happened?
- Where did events occur?
- What instruments were used?
- Why?
- How?
- When?

Crime Scene
Any place where an infraction or accident has occurred.
The geographical area where the incident occurred, and all elements related to it (eg. tools, weapons, cadaver, vehicles).
Thus, a 'crime scene' also includes places where the victim was discovered, where tools are recovered, and in cases where victim was moved, the place where the offence actually occurred.
Most physical evidence will be obtained here.

Scene type	Key reconstruction points	Key evidence
Car accident	Position of victims Position of vehicles Sequence of events	- paint - headlights - debris - tyre traces in order to identify the vehicle(s) and their state at the time of the accident
Fire/explosion	History of the development of fire Origin of event Ignition source	Soot pattern, etc. (See Fires and Explosions lecture)
Mass catastrophe Same problems as accidents, but on a much bigger scale.	What happened? Major problem is victim ID	Stuff for reconstruction and explanation purposes

Investigation
Goals:
- to make observations at the scene in a systematic and scientific manner
- to be as thorough as possible, since there won't be a second chance to make those observations.
Errors in protecting and examining the crime scene CANNOT BE RECTIFIED.

At the scene, in a timely, systematic and careful manner, the investigator must:

Intervene

Protect the scene

Safety

Access control

People

Preserve the evidence

Cadaver management

Document the scene

Note taking

Photography

lecture on photography

Crime Scene Sketching

Video

Process the scene

Searching

Evidence

Transfer between victim and scene

Transfer between perpetrator and scene

Transfer between perpetrator and victim

Single transfer

Double transfer

Chain of Custody
Evidence must always be accounted for; chain of custody ensures that the evidence collected at the scene is the same evidence being presented at court.
Container for evidence is tagged with sample code, agency, case number, crime type, victim/suspect's name, brief description of the item, name/initials of the collector, name/initials of everyone else who's handled it since it was collected, dates of item collection and transfer.
Evidence is sealed so that it is obvious when the packaging is opened, that it has been.
Once it has been proved that the Chain of Custody has been broken, then that piece of evidence is inadmissible in court and reflects very badly upon the lab.

Principles of Forensic Science - lecture ?

2008-09-17T16:21:37Z

Presumptive testing: A substance is definitely not substance X, and is probably substance Y. Generally [bio]chemical techniques.
Confirmatory testing: A substance is definitely substance Y. Generally immunological tests.
Biological materials: blood, semen, saliva, urine, faecal matter, vaginal secretions.

Substance	Presumptive tests				Confirmatory tests
Substance	Chemical	Immunochromatographic	Biochemical/Enzymatic	Other	Chemical	Immunochromatographic	Biochemical/Enzymatic	Other
Blood	Phenolphthalin (Kastle-Meyer) Tetra-methylbenzedine (TMB) Luminol Ortho-tolidine	Hema-trace
Seminal fluid	Acid phosphatase (ACP) Choline and spermine					P30 protein assay		View spermatozoa
Saliva			alpha-amylase assay		none
Urine

Principles of Forensic Science - 20080814 lecture 4

2008-09-17T08:10:28Z

Diagrams all taken from Xanthe Spindler's lecture notes.

Photography
Requires: light, instrument to capture light.
Generally the first technique used, since the interaction of light with a surface tends to be non-destructive.

Light: EM energy; visible light is only a small portion of the EM spectrum.

frequency = speed of light / wavelength

A light beam directed onto a surface is principally either reflected, absorbed, or transmitted.
Incident light: the initial light beam.
Irradiating intensity = Reflected intensity + Absorbed intensity + Transmitted intensity.

Opaque surfaces: No light is transmitted; all light not absorbed is reflected.

Reflected light: seen by eyes/camera. eg. White object means it reflects all wavelengths equally; no selective absorption, it will always appear the same colour as the incident light (initial light source colour).

Contrast = reflection of background - absorption of sample
Best contrast: when sample absorbs (or reflects) the highest amount of incident light.
Absorption spectrum: maxima
Reflectance spectrum: minima
More intense light != more contrast. (10 photons in -> 8 photons reflected is 20% contrast. 100 photons in -> 80 photons reflected is still 20% contrast. But you don't have to expose the film for so long.)
More intense light -> reduced exposure time.

Colorimetric techniques

Selective absorption: when incident light is white, but reflected light is coloured, absorption has occurred. eg. A blue object (under white light) has absorbed all other frequencies, and reflected the blue wavelength back. Therefore, if a green light was shone upon it, it would absorb those wavelengths and appear black.

Absorption properties (selective absorption) can be used to increase the visibility of an object by filtering the frequency of light that is interacting with the object.

The entire point of using different coloured light is to increase contrast between evidence and whatever it's sitting on, therefore enhancing visibility, and making it easier to make accurate photographic record of the evidence.
Thus, the only requirement of using filtered light is to make sure the background and the sample don't reflect the incident light back at the same wavelength. (Nothing useful is going to be seen if they both reflect red light back in equal amounts.) Under white light, background and sample may look very similar/indistinguishable; hence the use of filters.

Selective absorption is less sensitive compared to fluorescence methods.

UV absorption/reflection
Contrast between absorption/reflectance of UV rays by the surface vs that of the sample.
Results in light print on dark, or dark print on light.

IR absorption/reflection
Document examination
Ink differentiation
Revealing erased writings
Improving contrast of gunshot residue on fabric

Episcopic coaxial illumination

Makes use of the fact that while the background may reflect all the diffused light back at the source, the sample will not.

Polarised light
I have no idea why polarised light is used. But this is the concept:

Photoluminescence
Energy (light) absorbed by a molecule does not disappear:
Molecule in ground state + light (aka energy) -> molecule in excited state
Excited state + energy loss -> ground state

Methods of energy loss (all three may be used):
- photochemical transformation (chemical change, eg. film)
- heat transfer (vibrating/colliding with other molecules and giving the energy away)
- photoluminescence (emission of light); emitted light usually has less energy (longer wavelength) than absorbed incident light, since energy may have already been lost via the above 2 methods. However, for a particular molecule, the emission of light is always at the same wavelength, and thus is used for identification.

Fluorescence: when emission immediately follows excitation; emission delay < 10^-10 seconds.
Phosphorescence: delayed emission

Higher quantum yield (efficiency of photoluminescence) is desirable.
- This can be obtained by ensuring as much of the incident light is absorbed as possible (wavelength of max absorption), because then more energy will be emitted when the molecule returns to the ground state (luminescence visualisation is in the spectral region of max emission).
ie. Putting in more of the correct wavelength results in more of the molecule's typical output wavelength.
- Ensuring that as much energy loss is performed in the manner of photoluminescence also results in higher quantum yield.
- Cooling of sample, so no loss of energy through heat or vibration. Usually by liquid nitrogen.
- Observing the emission at the wavelength of max emission. (Like using X-ray sensitive film to detect X-rays, rather than a brick, which will tell you nothing.) Filter that absorbs incident light or other undesirable radiation, but transmits the wavelength to be absorbed.

Camera
Collects reflected light images, and record them.
Light -> lens aperture -> lens -> film or photosensor array.

Focal length: in mm. The minimum distance between centre of lens and film when focussed on infinity. Describes lenses.
Aperture: described with f-stop. The hole that lets light in. Small number = larger hole; opening aperture by one stop = double the amount of light. Affects the depth of field.
f-stop = Focal length / diameter of lens opening
Shutter: shutter speed, or exposure time, in seconds, or fractions of. Controls the amount of time that light is allowed into the camera for.
Aperture and shutter are used in conjunction to control the light entering the camera.
Depth of field: the area from foreground to background, which appears most in focus. Larger aperture = smaller f-stop number -> less depth of field -> sharp subject, blurry background.
Rule of thumb: focus 1/3 of the distance into the scene.
Max depth of field: short focal length lens, small aperture (large f-stop), greater distance to focal point.

Filters
A device that can be placed in front of or behind a lens to modify the light that enters the camera aperture.

Choosing filters:
Complementary colours darken observed colour, and increase contrast.
Adjacent colours lighten observed colour, and decrease contrast.

Modify spectral composition
Used for wavelength selection.
- interference filter: Optical interference. Available from UV through to ~14mm in the IR.
- absorption filter: Absorbs certain parts of the spectrum. Coloured glass, dye suspended in gelatin sandwiched between glass plates. Cheaper, but inferior to interference filters.

Does not modify spectral composition
- grey filter: absorbs a certain percentage of light evenly over the whole spectrum. Used when there is too much light, and/or shutter speed or aperture is fixed (microphotography)
- graduation filter: compensates for the fact that there is more light at the edges than at the center. Used with wide angle lenses.
- polarisation filter: for removing undesired reflected light from the sample. Ineffective with metallic surfaces, metal is a polarising substance; use 2 correctly orientated filters, one in front of light source and another in front of the lens. Limits shot angle.

Film
Negative film: produces negative image, used to form a print.
Reversal film: produces transparent positive, allowing most accurate colour reproduction
Film speed: measure of sensitivity to light.
ISO number = ASA / DIN
Faster film = higher ISO number -> more sensitive to light -> lower resolution, therefore grainier enlargements.

Photosensor arrays
Used in digital photography.
A series of semiconductor capacitors that convert light information (colour and brightness) into an analog electrical signal, for creating a digital image.
Colour is usually seen in rations of Red, Green and Blue.
CCD: Charge-coupled devices. Better quality images, less noise, and can be manufactured so that each sensor detects all three colours. Entire array needs to be scanned in series to create an image.
CMOS: Complementary semi-oxide semiconductor. Cheaper, can be manufactured on standard silicon chips, works at low voltages. Each sensor read individually.

Digital vs Film

Digital	Film
Pixels are uniform units	AgBr particles tend to be randomly shaped and distributed
Photosensor array is perfectly flat, always positioned perfectly on the focal plane	Position of different frames on the same roll of film not always completely reproducible
Instant results No processing costs Processing software varies enormously - algorithms are a black box	Processing required Poor quality photos aren't discovered until after processing Development process is expensive
Images can be easily altered, and can be done so undetectably. Possibility of fraudulent evidence delayed the introduction of digital photography.	Well understood and accepted by the courts
Resolution can be limited (although this is catching up) Easily enlarged/digitally enhanced	Low ISO number films have resolution superior to any digital medium
Relatively cheap memory cards Re-useable memory cards Compared to a roll of film, more photos will fit on memory media	Film is expensive - particularly good film
Limited to RGB; colour depth is still limited	Better colour reproduction (so far)
Work better at low light levels Originally developed for use with astronomy	Flash required for indoor work Care needs to be taken with multiple flashes and use of flash angles
Generally smaller and more robust equipment - Digital SLR	Film SLR cameras can be unwieldy and considerably more fragile
Easily transferred to a permanent medium	Film can degrade quickly if not preserved correctly

Be aware of the following:
Camera != human eyesight. Blue sensitive vs red sensitive.
Perspective and reflection/other types of distortion effects.
Photography is great for accurate documentation, but the technique can also introduce distortions.

Because digital photos can be easily altered, guidelines have been introduced so that digital photos are admissible in court.
Forensic Science Communications, Vol 5 No 1, January 2003

Principles of Forensic Science - 20080804 lecture 3

2008-09-16T14:43:41Z

Trace evidence: small or microscopic evidence generally left by transfer through contact between two objects. Based on Locard's principle.
Exploitation: how evidence is used.
Class identification: generally, what is it.
Selectivity: how well you can find what you want amongst the noise. How selective a class of identification depends on circumstances, lab capabilities and the database on which comparisons are run.

Classes of identification
(This should really be in a table.)

Papillary prints

Lip/ear/teeth marks

Biological samples
- biological stains
- hair and nails

Documents

Voice and sound analysis

Physical prints and impressions

Fibres

Paint and glass fragments

Chemical traces

Other
Firearms

Cartridge: cartridge case, primer, propellant, bullet.
Bullet: metallic projectile that leaves the muzzle of the firearm when discharged. Varied composition, size, shape.
Cartridge case: cylindrical tube that holds the primer and propellant
Gunshot residue: residual particles emitted from a firearm after discharge.

Collection:
Any gun must be considered to be loaded. Keep in mind that it will probably have trace evidence (fingerprints).
-Pistol: take note of hammer position, breech, magazine.
-Revolver: take note of hammer position, check cylinder for visible cartridges
-metal detector search for cartridge/case and bullet
-store metal stuff in separate plastic containers
-collect gunshot residue along with the surface if possible
-transfer by swab or adhesive sample holder
-store in paper
Exploitation:
-physical and chemical analysis
-classification and comparison
Expected results
-calibre (diameter of gun barrel)
-projectile and cartridge types
-manufacturer of cartridge
-type, brand or manufacturer of the gun that may have discharged the cartridge
-determining if gunshot residue is present (and if yes, how much, type, etc.)
-ID of gun that fired the cartridge
-ID of person who did the shooting
-shooting distance
-bullet trajectory

Light globes
A glass bulb containing a metal filament capable of emitting light on contact with an electric current.
Collection:
-note accident circumstances
-note light switch position
-collect bulb only; with vehicles/portable lamps, collect entire fitting
-do not break
-store in material that cushions shock
Exploitation:
-optical and physical examination
-comparison
Results:
-state of bulb at the time of shock
-type of glass and its uses

Knots
A network of flexible material or crisscross of two flexible objects executed in such a way that tightens when pulled.
Collection:
-collect entire knot
-never undo or modify
-transport with caution
Exploitation:
-physical examination
-microscopic analysis
-classification and comparison
Expected results:
-exclusion or description of a person
-ID of knot type
-corroborative evidence
-determination of craft/hobbies that require specific knotwork

Principles of Forensic Science - 20080731? lecture 2 cont.

2008-09-16T06:17:43Z

Interpretation of evidence and results of analysis should be based on objective parameters and probabilities.
The interpreter should let the results fit a number of possibilities. One should be aware of making the results fit one's own hypotheses.

Fallacy
High probability of the result given the hypothesis, does NOT mean that there is a high probability for the hypothesis, given the result.

Prosecutor's Fallacy: use of the above probability results to say that there is a high probability of the hypothesis of guilty being true

Defense attorney's Fallacy: use of the above probability results to say that there is a high probability of the hypothesis of innocent being true

Fallacy usually involves the improper multiplication of probability percentages.
Such a mistake is usually a mathematical example of ignoring the guideline that: evidence never stands alone; it must be put into context if accurate conclusions are to be made.

Transpose the conditional: forced to accept something that is not necessarily true.

Bayes Theorem and the Bayesian approach
Likelihood ratio = Probability of evidence if assertion is true / Probability of evidence if assertion is false.

LR = P(E| C,I) / P(E| !C,I) where:

LR is likelihood ratio

P() is probability of

E| is evidence available

C,I is contact between suspected source and receptor

The resulting figure is a ratio that tells us the strength of the evidence in supporting our hypothesis.
LR > 1 - evidence is in favour of the hypothesis.
LR < 1 - evidence does not support the hypothesis.
LR = 1 - evidence is neutral.
Magnitude of LR gives how strong the evidence is. It can then be used in a verbal scale, such as:
-10 = extremely unlikely
-5 = unlikely
1 = does not confirm or deny
5 = likely
10 = extremely likely

What is the probability of finding these types of evidence if the hypothesis is true?
What is the probability of finding these types of evidence given an alternative hypothesis?

Limitation of Bayesian approach is that missing data can greatly affect the resulting Likelihood Ratio.

Guidelines
It is not whether the hypothesis or evidence is true.
It is whether the evidence increases or decreases the likelihood of the hypothesis being true.

Evidence does not have value on its own.
Evidence is only valuable if it has a context.
eg. Knowing that there is a random blood spatter that belongs to person X over there is no help unless other information is available.

Evidence is valuable if it can distinguish between hypotheses.
eg. Knowing the suspect has a red car is not so great if everyone else in the area of the crime owns a red car too.

Don't assume malice when stupidity will suffice; but don't rule out malice. - Heinlein's razor

The Prosecution will usually have one hypothesis; the Defense will likely have an alternative hypothesis.

"This evidence is n times more probable if the accused left the stains than if some random did. The evidence therefore [very] [strongly] supports the proposition that the accused left the mark."

Considering evidence
What is the probability of the evidence if the hypothesis is true? (may require some probability maths)
What are the appropriate alternative hypotheses?
Why are these appropriate alternative hypotheses?
What is the probability of the evidence given the alternative hypothesis?
What is the value of the evidence?

Remark on the latest PFS lecture - 'War on Drugs'

2008-09-15T07:38:42Z

I do not think I have ever been so disgusted after a lecture before. If I have, I am fairly sure that this is the first time that I have been so disgusted at the actual lecturer, rather than the lecturer's ability to teach.

While I am aware that each person is allowed their opinions, I had always expected that an academic - particularly one who claims to be a scientist - would back up their viewpoints with sound logic and - considering that this is forensic science, a field fairly dependent upon probabilities - statistics, rather than excessively biased newspaper clippings, arrogance/apparent disdain for others' viewpoints, and rhetorical questions.

Such things are appropriate for speeches, debates, forums and the like, where people do need to be convinced. I suppose in that way, they are also useful for impressing ideas into students' memories. There was no effort to teach students to think or make their own, informed inferences. That is generally the case; it is not abnormal. But there was not even effort made to allow students to make their own informed inferences; we were told that 'this is how you should be seeing it, everyone else who gave serious time and thought into the matter are obviously wrong, and whatever ideas you may have about the topic are clearly rubbish'. I think that is what irks me most.

I'll admit to having mostly rubbish ideas, because I know they are. But I refuse to believe that the hours that others put into considering what sort of legislation surrounds drugs and enforcement concerning the entire topic are all rubbish. The ones who make the final decisions may be at fault. But it is not right to belittle everyone connected to the decision.

It is disgusting that the guest lecturer, who basically came to tell a personal story and the events that led to his forming an organisation to give support to families affected by drugs, has more of my respect than the man who apparently runs this subject.

Of course, this man is a university academic. I suppose it should only be expected that they're cynical to a fault. And since the guest lecturer's story is quite personal, it only makes perfect sense that he should pull at his audience's heartstrings. While both men's viewpoints are fairly similar and seem to stem from the same reason(s) (loss of many young Australian lives from drug overdoses, which are actually easily preventable), it disgusts me that the man who is supposed to have academic credibility is arrogant enough to present material in a lecture that is all one sided; he may have done some actual work, or have personal experience of how it affects him, but all he showed us were his letters written to newspapers - which he openly stated, were changed by the editors. (I do not care if he actually is a bitter old man; I'll give him the fact that he's old.)

At least he's obviously biased. Unlike some people who try to be subtle about it, or claim that they are not really implying this or that when in fact they are.

Principles of Forensic Science - 20080731 lecture 2

2008-09-14T16:43:09Z

Always go from the general to the particular.
Non-destructive tests, then destructive ones.

Individualisation: unique. Eg. Banknote number 12349876871317825123987613
Identification: an item shares a common source. Eg. $5 banknote

Identification properties
- morphology (white, round)
- composition (latex)
- time and space (found at 14:00 next to the bed)
- unique features (has a hole)

Scientific method
1. Examine objective data (existing data)
2. Form hypotheses
3. Critical reasoning (in a way that supports/disproves hypothesis; "What should I find (or not) if my hypothesis is correct?")
4. Examination and analyses
Does resulting analysis support the hypothesis? If not, go to 1; repeat as required.
5. Verify and validate.

Evaluating the method
Sensitive : Can it tell if this is redder than that red?
Selective : Can you find the fibre amongst all the other bits of dust?
Reliable : Will it give the same results every time? Tested using:
- comparison material
- references
- standards
- proficiency tests, quality insurance, are they up to date, etc.
- sometimes, multiple readings are not possible due to small sample size.
Non-destructive : Will the sample still be the sample afterwards?
Complementary : Can you do other tests on the same sample of evidence afterwards?
Simplicity : (zim zim zim...)
Rapidity
Cost : Because real life labs have budgets
In actual fact it doesn't matter what specific order/method is used, so long as it does as well as possible in the above evaluations, and that the scientist uses the same method every time.

Discriminating power (DP): the probability that two items selected at random from some population do not match with respect to some characteristics. In simpler terms, the probability that 2 random things won't match.
Higher DP occurs when:
- there is a large variation of a measured feature within the population (eg. a whole lot of matchsticks of different lengths)
- lower error in measurement (use precise measuring equipment)
- distribution of each feature is characteristic of the population (eg. long hair in men vs long hair in women)
- no correlation between two measured features (eg. a blue matchstick that can be a variety of lengths)
High discriminating power means matching properties is more significant. It does not mean the evidence is valuable. DP is just a technical concept; it's not very good at picking whether the evidence available in a particular context is out of the ordinary.

Judicial admissibility: can evidence be used in court, given that it was examined and analysed using procedure X, technique Y and principle Z?
- Frye standard: if the procedure/technique/principle is generally accepted by enough people in the relevant scientific community, then yes.
- Daubert case: prove to the judge that you are an expert qualified to give an opinion, then yes. In this instance, the trial judge is responsible for ensuring that the technique/theory can be and was tested and reviewed by peers, the error rate of the technique/theory, ensuring that there are and maintaining standards that control the technique, and seeing if the technique is accepted within the scientific community.
So, for example, a volunteer firefighter could be asked to give conclusions as an expert witness in court in an arson case; they may have no formal training in the lab, but they may have 20 years experience firefighting.

Screening techniques (see later lecture slides for more, later notes for better details)
Chemical reactions
These are destructive; they change the evidence. Therefore, use the one with the highest discriminating power.
Chemical screening : (colour, crystal); rapid, can be performed on scene. Usually for detecting danger (explosives) or trafficked goods (drugs). Results must be backed up in the lab.
Immunological screening : for testing blood, wine, urine, etc. Must be backed up in lab.
Colour reactions : for ease of observation. Ideally, they do nothing to what they're making clearer. However, they may destroy other trace evidence.

Destructive spectra techniques
Atomic absorption : detecting highly toxic elements when analysing hair, fingernail, paint, gunshot residue, fake coins, etc.
Laser and Inductively Coupled Plasma (ICP) atom emission spectroscopy : good for identifying guns/bullets and pollution.
Mass spectroscopy : for drugs, and what happens to them.

Separation techniques
These are all used in combination with other analytical processes to allow powerful DP requiring interpretation.

Chromatography
Thin layer for inks, fibre dyes, drugs, etc.
Gas for ignitable liquids
Liquid for drugs, paint, etc.

Capillary electrophoresis
inks, protein, DNA, enzymes

Isoelectric focussing
Blood products, proteins

Expert Report
Mission : aka Hypothesis. The issue or problem to be addressed, and the scope of work performed by the expert
Procedure : aka Minutes. Everything that was done to the examined items
Results : Observations. No bias; refer to hypothesis.
Discussion : Interpret the results
Conclusion : Answers to questions in the mission

How the jury or judge interprets the report is not up to the forensic scientist.

Other report types
Informal/Notice : often verbal
Scientific : a report written for other scientists, in such a way that they could reproduce the procedures used from the notes alone. Usually kept in a laboratory notebook. These need to be extensive, and the forensic scientist must be ready to produce one whenever the court chooses to ask for it; it is evidence. These notes are also good for referring to when the case is finally heard in court years later and one is questioned in court to clarify one's expert report.

Communications
There are numerous places where miscommunications can occur:
- information given to the forensic scientist from a large variety of sources
- colloquialism
- badly formed missions
- jargon
- reality vs judicial fact, eg. hearsay, which may be right, but wouldn't be admissible in court
- oversimplification or overly complicated explanations may change the value of evidence as perceived by jury/judge
- no international standards eg. fingerprinting number of matching points differs from country to country
- the aim of the forensic scientist, which is to report what was found via evidence examined, vs the aim of the law, which is to deal with humans

Principles of Forensic Science - 20080728 lecture 1

2008-09-14T10:42:34Z

Goal of forensic science:
1. Is it a crime?
2. Who committed it?
3. How was it committed?

Broad overview of what happens in the lab:
1. Form hypothesis
2. Find evidence to support the hypothesis (or not)

Role of the forensic scientist:
1. Bring proof/evidence as appropriate to their area of expertise (specialty)
2. Report results and conclusions in a way that regular people can understand
A forensic scientist is to be the advocate of truth; there should be no bias, since a person's liberty usually relies on the result of their investigative work.

Evidence: anything legally submitted to a competent tribunal for the purposes of ascertaining the truth of the matter being investigated. Also known as 'trace'.
Testimonial evidence: statement under oath; answers to questioning.
Physical evidence: objects; stuff. Usually something that a forensic scientist can perform tests on in the lab.

The entire point of physical evidence:
- prove a crime was committed (or not)
- support given testimonies (or suggest that the given testimony was a lie)
- form links between suspect, victim, and crime scene
- ID people associated with a crime
- is to be useful and relevant to the incident

Locard's Exchange Principle:
Every contact leaves a trace; persons at the crime scene leaves something that was not there before, and takes away traces that were not associated with them before they arrived.

Morphological features: the physical properties of an item of evidence; things that are out of the ordinary with it.
Chemical composition: ... duh.
Permanence and stability: How long the evidence will last
Frequency distribution: stuff to do with statistics, eg. How common is this particular item of evidence in everyday life? What is probability of the item being found where it was / having a particular characteristic compared to other similar items in existence?
Composition variation: More statistics; eg. Paper has a large composition variety, but can still be called paper. For other things, that's not so true.

Historical landmarks of forensic science
André Vesale: victims of violent death
Ambroise Paré: ballistics, gunshot wounds
Mathieu Orfila: toxicology
Daguerre: photography
Alphonse Bertillon: criminal anthropometry
Faulds, Vucetich, Galton, Henry: dactiloscopy
Abbe, Stephenson: condensing lens (microscopy)
Mendel, Landsteiner, Dongen, Hirschfield, Jeffreys: forensic biology

Exposure - Light tutorial

2008-05-31T21:25:58Z

Unfortunately I slept in so I missed the first hour where they talked about sunlight.

Some miscellaneous notes not related to the four categories below:

When shooting portraiture, bring the subject forward, so they are further away from the background. The background then becomes more blurred, so that there is more focus on the person. This also has something to do with lens and focus.

Grey card - a card that reflects a known amount of light back at the light source. 18% grey is most commonly used; an 18% grey card reflects 18% of its light back to the camera.
The point of using one is to tell the camera what white is. It's possible to just point your camera at a sheet of paper and get the white off that. (I'm not sure if this paragraph is even accurate.)

Metering - when shooting (pictures of) people, use spot metering, point it at the skin tone, and use that for the photos. Particularly useful if your subject has dark skin and is wearing bright clothing.

When subject is facing the sun, they will have a tendency to squint.
Having the sun behind the subject makes for very extreme exposures.
Direct, noonday sunlight results in sharp shadows.
Shooting with the sun side-on may give a 'sculpted' look, from the shadows formed.
Lens hoods are useful for shading the camera lens from sunlight. Best used when sunlight is to the side/something around 45 degree angle?

Shade has less harsh lighting; the light is already diffused for you when in the shade. It's also cooler for both model and photographer. Good to use when you are a solo photographer.

Deckker bought a 4-in-1 reflector kit: Diffusion, gold, silver, black.

Diffusion reflector is a sheet of translucent material that (not surprisingly) diffuses light. Also known as the photographer's portable clouds. Good for fixing those extreme shadows that result from shooting in direct sunlight.

Gold reflector gives a warmer tint to the reflected light. Some people like it, some don't. I think it works best when it's subtle, but I'm not that observant so I tend not to notice it until the difference is blatantly shown to me in before/after photos.

Silver reflector reflects light as it is, with minimal diffusion. Fairly easy to understand. Also quite glaring, so use sparingly, and preferably not at an angle where it will make the subject squint. (Unless you actually want the subject to squint.)

Black reflector absorbs light. It's used for when you want to give better definition to your subject, or to control lighting better. (Well duh, that's the point of this entire tutorial). For example, you know how you want your subject to be lit up, and you don't want other light sources to interfere/be bounced off a surface onto the subject - strategically place a black reflector to do the job.

Also known as flash. Not constant lighting.
The smaller the light source, the harsher the light is going to be.
You can get detachable flash that goes off when it senses another flash has gone off nearby. This is useful for providing lighting from more than one source - perhaps light from the other side of your camera's flash.

Using more than one source of light results in having to deal with multiple shadows. (This may be desired for artistic reasons.)
Really strong, multiple flashes can light up a big room.
You can also bounce flash off something, although due to the inverse square law, this may be difficult.

Those huge umbrella things with lights behind them. Advantages to using them include being able to set up light just how you want it, softer light, automatic triggering of diffused flash light.
Disadvantages include heat (everything melts/sweats/etc), cost of equipment, and depending on the sort of light used, you may need extra equipment to make it look good.

Visual Language Lab 9

2008-05-15T06:39:38Z

Holding down alt, hovering between layers and clicking when the mouse pointer changes to two overlapping circles, toggles applying it to just the layer immediately below, or make it apply to everything layer below.

Fill layer: allows changing of the fill colour at any time, without damaging the actual image.

Holding down alt and hovering between two layers allows an instant creation of a clipping mask; the cursor will change to an image of overlapping circles. The layer on the bottom acts as the selection of what to show, and the layer above is what shows through.
This works with shapes (like text) on the bottom layer.
This also works with images as the bottom layer, but you need to make a selection in the bottom layer first. Nothing happens otherwise.